Is it possible for a bad power steering pump to cause excessive play in the steering?

I seem to wander on the road quite a bit and everything else seems to check OK.

Not likely..Jack it up and put it on stands, mke sure the stands are under the frame and not any of the suspension..Lock the steering wheel, and wiggle a tire with your hands, you should be able to pin point the play, it might take two, one to move the tire back and forht and one to watch the tierod ends, gearbox, steering shaft..Good luck

Did you solve the problem?

Everything checks out after two alignments but is still like balancing a broomstick at 75MPH.

I have a '98 XLT 4DR 4X4

I had a '98 2DR that was more stable than this one.